Analysis of giant extracellular hemoglobin from Glossoscolex paulistus (HbGp) and ionic surfactants interaction by isothermal titration calorimetry

• Grant number: 11/09863-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2012
• End date: February 28, 2014
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Marcel Tabak
• Grantee: Fernanda Rosa Alves
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Extracellular hemoglobin from Glossoscolex paulistus (HbGp) annelid is a gianthemoglobin, presenting a molecular mass of 3,6 x 106 Da. HbGp oligomeric structure is constituted by a hexagonal bilayer, and its dissociation leads to the formation of 1/12 of the whole native protein. Due to its extracellular nature and high resistance to auto-oxidation, as compared to vertebrate hemoglobins, the extracelular hemoglobins have been under focus as a possible useful system to develop therapeutic blood substitutes. The interaction between HbGp and surfactants gained a particular interest, once the surfactants are widely employed in biochemistry and biotechnology for protein solubilization, purification, characterization and determination of protein structure. The present research project is proposed aiming to evaluate the specific sites of ionic contact in the protein surface, as well as, the unfolding mechanism, including the oligomeric dissociation and the auto-oxidation processes, induced by several surfactants of known molecular structure. In this way, the interaction between HbGp and these surfactants, upon variation of concentration, provides a significant information in relation to the protein oligomeric state. However, the complete characterization of these interactions demands the quantification of the binding affinity, number of binding sites and the thermodynamics of binding, that altogether give us relevant information on the energetic and forces responsible for the biomolecular interactions. Moreover, this project aims to explore the use of the isothermal titration micro-calorimetry (ITC) for the thermodynamic characterization of the HbGp-surfactants interactions, pursuing a better understanding of the mechanism involved in these interactions. (AU)

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CARVALHO, FRANCISCO A. O.; ALVES, FERNANDA R.; CARVALHO, JOSE W. P.; TABAK, MARCEL. Guanidine hydrochloride and urea effects upon thermal stability of Glossoscolex paulistus hemoglobin (HbGp). International Journal of Biological Macromolecules, v. 74, p. 18-28, MAR 2015. (11/09863-6, 13/09349-6, 13/09829-8)

ALVES, FERNANDA ROSA; CARVALHO, FRANCISCO ADRIANO O.; CARVALHO, JOSE WILSON P.; TABAK, MARCEL. Glossoscolex paulistus Extracellular Hemoglobin (HbGp) Oligomeric Dissociation upon Interaction with Sodium Dodecyl Sulfate: Isothermal Titration Calorimetry (ITC). Biopolymers, v. 101, n. 10, p. 1065-1076, OCT 2014. (11/09863-6, 13/09349-6, 13/09829-8)

CARVALHO, JOSE WILSON P.; ALVES, FERNANDA ROSA; BATISTA, TATIANA; CARVALHO, FRANCISCO ADRIANO O.; SANTIAGO, PATRICIA S.; TABAK, MARCEL. Sodium dodecyl sulfate (SDS) effect on the thermal stability of oxy-HbGp: Dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) studies. COLLOIDS AND SURFACES B-BIOINTERFACES, v. 111, p. 561-570, NOV 1 2013. (09/17261-6, 11/09863-6, 10/09719-0)

BARROS, ANA E. B.; CARVALHO, FRANCISCO A. O.; ALVES, FERNANDA R.; CARVALHO, JOSE W. P.; TABAK, MARCEL. Denaturant effects on HbGp hemoglobin as monitored by 8-anilino-1-naphtalene-sulfonic acid (ANS) probe. International Journal of Biological Macromolecules, v. 74, p. 327-336, MAR 2015. (11/09863-6, 13/09829-8)

CARVALHO, FRANCISCO ADRIANO O.; CARVALHO, JOSE WILSON P.; ALVES, FERNANDA ROSA; TABAK, MARCEL. pH effect upon HbGp oligomeric stability: characterization of the dissociated species by AUC and DLS studies. International Journal of Biological Macromolecules, v. 59, p. 333-341, AUG 2013. (09/17261-6, 11/09863-6, 10/09719-0)